1. Field of the Invention
This invention concerns roof beams, especially for use in constructing conservatories and like structures having roofs comprising panels usually of translucent material supported between roof beams.
2. Description of the Related Art
Translucent panels for conservatory roofs are generally sandwiched at their edges between upper and lower roof beam forming extrusions or cappings coupled to a glazing bar, usually of aluminium. To provide a good seal above and below the translucent panels, provisions are made for the roof beam to retain gaskets in suitable positions.
Upper roof beam forming extrusions or cappings may have gaskets formed integrally with panel contacting edges thereof and gaskets for the underside of the panels are usually retained in special formations of the aluminium glazing bars. These gaskets have to be fitted to the extrusions on site which takes up time. Also, the extrusions are more expensive to produce because of the additional gasket retaining formations required.
Furthermore, in order to retain the lower beam forming cappings, the aluminium glazing bars require further formations on which the lower beam cappings can locate.
In our co-pending British Patent Application No. 2275958A it was proposed to provide a roof beam construction for use in constructing conservatory roofs comprising a glazing bar and upper and lower cappings therefor having gaskets formed integrally on edges thereof between which a roofing panel is to be retained and means for locating the cappings on said glazing bar, wherein the means for locating the lower capping on the glazing bar comprises the integrally formed gaskets, which in use are trapped between the glazing bar and roofing panel.
The lower cappings are formed with either a flat base or with a base having a pair of angled longitudinal facets. For each type of capping the glazing bar, generally an inverted T in section, has its cross bar correspondingly shaped, i.e. either flat or with two angled facets. In forming Victorian style conservatories, both types of glazing bar will usually be used. The glazing bars with the flat base and corresponding cappings are usually used as transom bars extending from opposite sides of a ridge of the conservatory to the eaves and the angled base glazing bars with corresponding cappings are used for forming the Victorian roof end, which is formed with triangular section roofing panels. Thus, in forming a Victorian style conservatory, two different types of glazing bar and lower cappings are required, which adds to the cost. Furthermore, care has to be taken when erecting such a conservatory to ensure that glazing bars are installed in the correct positions.